[LLVMdev] FYI: Planning to remove ProfileInfo and related passes from LLVM

[#ALOK PRAKASH#]

Hello Alastair,

Yeah like I said, I was not aware of the new profile framework being developed. Interestingly BPI and BFI didnt turn up in any searches either. Anyway, I will take a look at them and see how they differ from the existing tools. 

Profile.pl is understandably a very simple script, but it does make it easier to see some preliminary profile results and identity the hot portions of a program which are suitable for hardware acceleration. llvm-prof also helps in the same way. 

Cheers,
Alok
________________________________________
From: Alastair Murray [alastairmurray42 at gmail.com]
Sent: Monday, 16 July, 2012 9:47:54 PM
To: #ALOK PRAKASH#
Cc: llvmdev at cs.uiuc.edu
Subject: Re: [LLVMdev] FYI: Planning to remove ProfileInfo and related passes from LLVM

Hi Alok,

On 16/07/12 12:41, #ALOK PRAKASH# wrote:
> I have been using the Profile.pl and the related passes and
> optimizations for about 4 years now. With every new release lately, the
> support for the profile scripts and their framework seemed to be
> downgrading. Hence, I used my own tiny one line fixes to keep them
> working. I offered to send these small patches to keep these scripts
> working, to the LLVM dev so that others can use it if they want. I think
> my email got lost that time, in the sea of emails we see on the dev mail
> list.

profile.pl has seen a non-cleanup related commit in 5 years ...  It
seems so simple I'm not sure I see a need for it.  But clearly you use it!

> I must confess that I was not aware of the BPI and BFI infrastructures.
> The breaking of the profiling infrastructure always baffled me. Now it
> makes sense, since it has been superseded by these new frameworks.
>
> Anyway, if you guys decide to keep the old profiling framework, it would
> be good. As Alastair has mentioned, the llvm-prof helps in a way for
> instrumenting the code with the profile data. Maybe this is also part of
> the BPI/BFI in which case it's great.

If a new profiler loader based on BPI gets written then llvm-prof could
be rewritten to use the BFI system without too much difficulty.

I found llvm-prof useful for examining the behaviour of profiling
support within LLVM, but I'm curious about what you use it for.  It
seems quite limited for performance analysis.

Regards,
Alastair.